It is known in the prior art to cover a decorative material such as wood with a transparent or translucent varnish to obtain a decorative piece that is pleasing to look at and touch and that withstands wear, like that described in document US 2005276874. However, the method for manufacturing the disclosed decorative piece is complicated, since it in particular has the drawback of requiring a second step during which a fastening portion is made on the back of the piece.